1. Field of the Invention
This invention relates to a method for manufacturing a sealing ring with a sealing lip, in which the material forming the sealing lip is extruded in a plastically deformable condition through a ring nozzle and is cut to length before or after solidification, thereby forming a hose-shaped sleeve. The sealing lip of the sealing ring is provided, in the vicinity of the zone causing the dynamic seal in the completed sealing ring, with hydrodynamically-acting return-transport properties. The sleeve is slipped onto a shaped tool which continuously widens the diameter of the sealing ring and having a flanged sealing lip.
2. The Prior Art
German Patent No. 32 46 152 discloses the manufacture of a sealing ring having a sealing lip with hydrodynamically-acting return transport properties. These properties are generated in the sealing lip of that reference after the solidification of the material forming the sealing lip and such generation requires a separate operating step. Hydrodynamically-acting return transport properties have also been generated in the sealing lips of sealing rings of the prior art by chip removal or by perpendicular pressure on the surface of sealing lips by an embossing tool. The need exists, however, for a method of manufacturing a sealing lip with a sealing ring having hydrodynamically-acting return transport properties which does not require a separate operating step to impart those hydynamically-acting return transport properties to the sealing lip of the sealing ring. The need also exists for a method of manufacturing a sealing ring having a sealing lip with hydrodynamically-acting return transport properties which is completely leakage free. Further, the need exists for a method of manufacturing a sealing ring with a sealing lip having hydrodynamically-acting return transport properties which has an increased service life and an improved resistance to abrasion.
It is therefore an object of the present invention to provide a method for manufacturing a sealing ring with a sealing lip having hydynamically-acting return transport properties which does not require a separate operating step to impart the hydrodynamically-acting return transport properties to the sealing lip during extrusion of the sealing ring.
It is a further object of the present invention to provide a method for manufacturing a sealing ring with a sealing lip having hydrodynamically-acting return transport properties which is completely leakage free.
It is a still further object of the present invention to provide a method for manufacturing a sealing ring with a sealing lip having hydrodynamically-acting return transport properties which has an increased service life and an improved resistance to abrasion.
Other objects and advantages of the present invention will be in part obvious and in part hereinafter pointed out.